Combined magnetic and manual switch



Sept. 23, 1952 v w. G. BOURNE 2,611,343

COMBINED MAGNETIC AND MANUAL SWITCH Filed June 7, 1949 Patented Sept.23, 1952 UNITED STAT COMBINED 'MAG'QNE'rIo AND MANUAL swrron WilliamGeorge Bourne, Acton, London, England, assignor to Rotax Limited,London, England Application June 7, 1949, Serial No. 97,585 In GreatBritain June 12, 1948 This invention relates to electric switches of thepush-pull type, and has for its object to' provide an improvedconstruction wherein an electromagnet is employed for holding the switchin either of its operative positions.

The invention comprises the combination of an axially slidable contactactuating member, an annular electromagnet winding surrounding the saidmember, a pair of pole pieces associated with the winding and spaced atany appropriate'distance apart, and an armature located between the polepieces and carried by the slidable member.

In the accompanying drawings:

Figure 1 is a longitudinal section illustrating one embodiment of theinvention.

Figure 2 is a fragmentary end view of a mem-- ber carrying the movablecontact pieces.

Referring to the drawings, the axially slidable member a is of hollowcylindrical form and is made mainly of insulating material. This memberis carried by a pair of annular supports 1), c in the body of theswitch. The support is of cylindrical form and is made from insulatingmaterial. Also it is formed with a number of radial slots (see Figure 2)in which are accommodated free metal contact pieces :1 and d which reston the outer surface of the slidable member a and which are loaded byspring blades e connected to terminals f on one end of the said support.Also on the adjacent part of the slidable member is embedded orotherwise mounted an annular contact piece y, the arrangement being suchthat when the slidable member is moved from its neutral position to oneof its end positions the contact piece y can bridge the contacts d andsome of the contact pieces d and when moved in the opposite direction toits other end position it can bridge the other contact pieces al To meetthis condition each contact piece d is shaped as shown to an L-form, andhas one limb situated at one side of the annular contact a, so that thelatter is brought into contact with the said limb when moved from itsneutral position in one direction only. Also each contact piece 11 isshaped as shown to a shallow U-form, and spans the adjacent part of theannular contact g, so that movement of the latter in either directionfrom its neutral position brings it into contact with a limb of eachcontact piece 02 Any desired number of contact pieces are provided, eachbeing accommodated in its own slot in the part c.

The other, 11, of the above mentioned supports consists of a hollowmetal ring carried by the body of the switch.

3 Claims. (01. 200-87) V 2 v v On the slidable member a is secured aniron sleeve h which is held against rotation by key pieces ion a part 7'secured to the body or housing of the switch, the said pieces 2'engaging longitudinal grooves min the sleeve h. Around the sleeve itthere is mounted in the body an annular iron core part it forming partof an electromagnet and carrying an exciting windingo. At one end of thepart 12 is formed a flange p forming a pole of the magnet, and extendingfrom this is another (and cup shaped) iron part (1 forming a second poleof the same polarity as 11. Between the parts p, q there is secured tothe sleeve h an iron ring r serving as the armature of the magnet.

On the outer end of the sleeve h is secured a push-piece s, and slidableon the sleeve is provided a pull-piece t, a spring it being arrangedbetween the parts s, t. In the push-piece t may be provided a window 1;which can be illuminated by a lamp bulb w when the switch is in eitherof its operative conditions, a holder at being provided in the interiorof the member a for carrying the bulb. The circuit through the lamp bulbmay be controlled by any one of the contact pieces d and the contactpiece 9. The circuit of the electromagnet may be controlled either bythe contact pieces d, 12 g or by a separate switch.

The mode of action of the switch is as follows:

On pushing the push-piece s inwards against the springs u, z, thecontact piece g is caused to bridge the contact pieces d which arethereby encountered by the piece g, and the member a is then heldagainst return movement by the interaction of the magnet parts 1, q. Thereturn of the member a to its neutral position is efiected by thesprings u, a, after interrupting the circuit of the winding 0 by aseparate switch, or by exerting a sufficient pull on the pull-piece t toseparate the parts 1", q. The member a is then held in its neutralposition by the springs 2, 2.

To close other circuits associated with the switch, the pull piece t ispulled outwards into contact with the inner end of the push piece sagainst the spring u. In this action the contact piece 9 is caused tobridge the contact pieces d, d which are encountered by the piece g inthis movement. Also the magnet part 1' is moved into contact with thepart 10, for holding the switch in this condition. During the outwardmovement of the member a the spring 2 is compressed by the part 1'through the medium of a sleeve 4 on the part h. Return of the member ais effected by the spring a after interrupting the circuit of thewinding 0 or by exerting suflicient pressure on the push piece 8 toseparate the parts 1', p.

By this invention electromagnetic retention of the slidable member ineither of the opposite operative positions of the slidable member iseffected in a very simple and convenient manner, and when a lamp isincluded, the condition of the switch is indicated by the lamp.

The invention'is not, however,restricted to the example described, assubordinate constructional details may be modified to suit difierentrequirements.

Having thus described my invention what I claim as new and desire tosecure by Letters Pat- 5 ent is:

1. An electric switch of thepush-pulltypemomprising in combination anaxially slidableccongtact-actuating member, an annular contactpiece onsaid member, a stationary annularelectromagnet surrounding said memberand having a pair of pole pieces of the same polarity arranged inaxially spaced relationship around said member, an armature-secured onsaid member and movably located between said pole pieces so that thelatter'can serve by magnetic interaction-with-said armature toretainsaid member in two difierent positions, and spring-loaded contactpieces shaped and arranged'so'thatiin-each of:said positions of saidmember at least some ofsaid spring-loaded contact pieces are bridged bysaid annularrcontact piece.

'-2.- An electric switch'as claimed'inclaim land having a pus'h piecesecuredon one end of said contact actuating member, a pull pieceslidably mounted on said contact actuating member at a position adjacentto said push piece, and a spring located between and acting on the pushand pull pieces to permit relative movement thereof.

3. An electric switch as claimed in claim 1 and having an ironsleevesecured on saidscontact ac- 't'uatingmember," an iron annulus secured onsaid sleeve and forming said armature, and a spring zopposing movementof said armature in one directionand arranged between said sleeve andsaid 'electromag'ne't.

WILLIAM GEORGE BOURNE.

REFERENCES CITED Filheifollowing :references are of record in the fileof this patent:

UNITED STATES PATENTS

